Gooseneck trailers have long been known in the art for use to haul various types of cargo. Gooseneck trailers are equipped with a coupling device such as disclosed in, for example, U.S. Pat. No, 5,382,109 to Nyman. As illustrated in FIG. 1, the coupling device 10 comprises a stationary plate 12 which is integrally formed to include a recess 14. The recess 14 substantially conforms to the spherical contour of the distal end of a towing ball 16 of a type well known in the art. A lock plate 18 is secured in locking position by means of an actuator 20 including a latch pin 22 and a manually operable handle portion 24.
When not in use, it is desirable to lock the hitch of a gooseneck trailer to prevent unauthorized hitching or unhitching of the trailer. Toward this end, a number of gooseneck trailer locks have been developed. Examples of these are disclosed in U.S. Pat. No. 5,520,030 to Muldoon, U.S. Pat. No. 6,109,078 to Marshal and U.S. Pat. No. 6,880,368 to Ulbrich et al. The locking devices developed to date typically suffer from a number of shortcomings. For example, the locking devices disclosed in the Muldoon and Marshal patents are long and unwieldy. As a result of their size they are also difficult to store and maintain readily at hand when needed for use. The locking device in the Ulbrick et al reference incorporates a relatively small locking pin and cooperating padlock to secure the lock plate of the coupling device in the locked position and thereby prevent connection to the towing ball of a vehicle. It should be appreciated, however, that the device does not prevent removal of the entire coupler from the trailer and replacement with another coupler which a thief can then use to tow the trailer away.
It is therefore clear that a need exists for a new and improved gooseneck trailer lock that prevents unauthorized connection of a trailer to a towing vehicle as well as removal of the coupler from the trailer. Advantageously, the present invention performs these functions while being both simple in design and inexpensive to manufacture.